Testing systems (e.g., spin stands and/or other suitable test equipment) are used for multiple purposes with respect to hard disk drive (HDD) disks, including disk characterization, testing, and development. Based on the results provided by these testing systems, changes in the manufacture and design of the disks can be made. In particular instances, the testing systems may perform an HDD initialization process that can involve measuring the touch down (TD) behavior of the head (e.g., behavior of the head and the media as the head comes in contact with the media) before and after a sequence of operations. If the touch down behavior changes by more than a certain degree, then the head media interface (e.g., head and media spacing) is determined to be defective and the head and media pair can be considered as a failed component. This type of event can be referred to as a TD delta failure. Preventing media that may be likely to cause a TD delta failure in the HDD from being manufactured or from being supplied to the HDD assembly operations can be important to keeping the total cost of HDD manufacturing under control.